public class ComPuter {
    public void powerOn() {
        System.out.println("打开计算机");
    }
    public void powerOff() {
        System.out.println("关闭计算机");
    }
    public void useService(Usb usb) {
        usb.OpenDevice();
        if(usb instanceof Mouse) {
            Mouse mouse = (Mouse) usb;
            mouse.click();

        }else if(usb instanceof Keyboard) {
            Keyboard keyboard = (Keyboard) usb;
            keyboard.inpurt();
        }
    }
}
